Where are Custom Content Type Definitions Stored

Question

When custom content types are created using Visual Studio where are the deployed definitions located? I have retraced the ones we have developed and removed them from the farm but my site collection still shows it at a valid content type in the library. Attempting to delete it yields error saying it is part of a solution and prevents me from deleting it. So... I want to find where it is and delete it! I was expecting it in the FEATURES folder but it is not there. SharePOint must think it remains somewhere but where?

Thanks

Answer 1

If you are unable to delete content type in your site collection (it says that your content type is still in use even if you are sure you deleted all references) try to empty your web and site collection recycle bins.

If your recycle bins still holds items or lists based on your content type you will be unable to delete it.

Edited: I am 99% sure that CT definitions are stored in database.

Answer 2

Make sure that your site collection does not contain any lists or fields which are based on your content type. If yes, then delete them first. Also as Vedran mentioned, clear the lists,fields and content types from your recycle bin too.